Limitation
As a measure of toxicity, LD50 is somewhat unreliable and results may vary greatly between testing facilities due to factors such as the genetic characteristics of the sample population, animal species tested, environmental factors and mode of administration.
There can be wide variability between species as well; what is relatively safe for rats may very well be extremely toxic for humans, and vice versa. For example, chocolate, harmless to humans, is known to be toxic to many animals. When used to test venom from venomous creatures, such as snakes, LD50 results may be misleading due to the physiological differences between mice, rats, and humans. Many venomous snakes are specialized predators on mice, and their venom may be adapted specifically to incapacitate mice; and mongooses may be exceptionally resistant. While most mammals have a very similar physiology, LD50 results may or may not be directly relevant to humans.
A low LD50 in animals is always a cause for concern for humans, but a high animal value does not guarantee that a substance is similarly harmless to humans.
Read more about this topic: Median Lethal Dose
Famous quotes containing the word limitation:
“...to many a mother’s heart has come the disappointment of a loss of power, a limitation of influence when early manhood takes the boy from the home, or when even before that time, in school, or where he touches the great world and begins to be bewildered with its controversies, trade and economics and politics make their imprint even while his lips are dewy with his mother’s kiss.”
—J. Ellen Foster (1840–1910)
“Liberty has never come from the government. Liberty has always come from the subjects of the government. The history of government is a history of resistance. The history of liberty is the history of the limitation of government, not the increase of it.”
—Woodrow Wilson (1856–1924)
“The French are certainly misunderstood:Mbut whether the fault is theirs, in not sufficiently explaining themselves; or speaking with that exact limitation and precision which one would expect ... or whether the fault may not be altogether on our side ... I shall not decide.”
—Laurence Sterne (1713–1768)